It's more likely that Tinsley was able to see a winning position much closer to the present than that, without bothering about the details of how exactly the winning position 6 turns in the future converted into an actual win 64 moves in the future.
it's less about how much he calculated in that moment and more about the accuracy of his confidence and the work he had to have put in alongside his talent prior to that moment to achieve that confidence and back it up.
Like, if you're in a chess midgame, there might still 6 major pieces and 4 or 6 minor pieces and tons of pawns on the board. It's tricky to calculate far into the future. At each node, there's easily dozens of possible moves, and 4-8 viable or not-horrible ones. That's becoming a lot of possibilities to consider very quickly.
In an endgame, there's like, 2 kings, 2 pieces and 4 pawns or a similar constellation. There's 6 possible moves, 3 of them immediately lose and 3 are worth thinking about. 2 of them probably only have one possible answer. Suddenly even an utter beginner like me can calculate 4-8 moves. A master-level player probably knows the endgame entirely, or can see 10 - 20 moves into it easily, because the branching factor is a lot lower now.
That is a matter of opinion. Looking a certain number of "moves ahead" is an important metric in game engines and also something that human players will tell you that (1) they are consciously doing and that (2) is important to them. So it's worth discussing on its own terms.
This is why chess programs usually say “mate in 24” but humans would more likely just be looking a few moves ahead to get in a ‘winning position’ which they know is an eventual checkmate.
I’m not good at chess, and don’t calculate more than 5 moves ahead, but have ‘spotted’ a mate 20 moves ahead just because you recognise that a certain position is winning even if you don’t know every single possible move and response.
we look ahead in ways like "doing this leaves this area weak, and the opponent has resources that can take advantage of that, and i cannot intervene on those resources in time" or "if i create a strong threat then the opponent will be forced to react to it, here are the ways they can react that make any sort of sense, here is what i can do in each of those situations"
they are not doing things like "let me simulate moving every one of my pieces right now, and then every one of my opponents pieces in response to each of those moves, and then my options again, and review 10,000 possible scenarios in my mind individually for the best min/max situation" like a classical computer engine does.
so i always find the "X moves ahead" phrase misleading at best. but as i originally stated, it is useful to know how many moves of perfect play are necessary for someone to convert a winning position when reviewing the players confidence going into that position. and even then you dont know if they got lucky or earned that confidence by looking at just the one game alone. Over the course of their career the amount of time that their confidence pays off or not tells the story there
Note that the first quote agrees with me:
> Not being a checkers player, I thought, "what does he know, my computer is looking 20 moves ahead." But a few moves later, the computer said that Tinsley had the advantage and a few moves after that I resigned.
We know as a matter of literal truth that the computer is looking 20 moves ahead, but it doesn't need 44 moves to realize that it's losing, even though the other guy says that recognizing the win would require looking 64 moves ahead. That guy was wrong; recognizing the win didn't require looking 64 moves ahead. He just had trouble imagining other methods of recognizing a win.
